Prehistoric juvenile rheumatoid arthritis in a precontact Louisiana native population reconsidered.

Descriptions of skeletal pathological conditions evident in the prehistoric Tchefuncte adolescent 16ST1-14883b are clarified. The basis is reaffirmed for assigning to the described pathological conditions a diagnostic perspective of juvenile rheumatoid arthritis or juvenile Lyme disease--a disease that mimics juvenile rheumatoid arthritis in its arthritic presentation--rather than of assigning them as representative of juvenile onset ankylosing spondylitis or other juvenile spondyloarthropathies. A hypothesis (Lewis [1994] Am. J. Phys. Anthropol. 93:455-475) is restated that 1) the spirochete Borrelia burgdorferi was the infectious agent responsible for prevalence of adult rheumatoid arthritis in prehistoric southeastern Native American populations, 2) that B. burgdorferi is a possible cause of the arthritis evident in individual 16ST1-14883b, and 3) that antibodies to B. burgdorferi provided partial immunity to the related spirochete Treponema pallidum for the 16ST1 precontact Tchefuncte population from Louisiana, protecting them from severe treponemal response. Given the probable widespread existence of Ixodid tick vectors for B. burgdorferi in prehistoric North America, coupled with the existence of treponematosis, it follows that the transition of Native American hunting-gathering economies to more sedentary economies would predictably be linked to an increased incidence of treponematosis due to the loss of benefits of the above-stated partial immunity. In other words, as prehistoric Native American exposure to tick vectors for B. burgdorferi decreased, susceptibility to treponematosis increased. Inferences regarding biological controls interacting with and influencing prehistoric Native American migration patterns are suggested from the link of B. burgdorferi to an Ixodid tick common to northeast Asia.